AC-DC 12V 5A adapter for my DC-DC ATX PSU

I am looking for a small AC-DC adapter that gives at least 12V@5A for my carputer with DC-DC PSU. Anyone can recommend one?
I want something small that I can leave in the car when i use the carputer for a party and such... I have a benchtop PSU that
s 12V@30A but its too big to carry around, and a computer AT/ ATX type power supply is just too big n ugly =p

How about a small computer supply? Grab one from an AT slimline case. Probably as small as you are going to get. Standard "adapters" are liner, meaning they have a friggin' huge transformer. For 5A at 12V, this would be about the size of a baseball.

I use a 3A supply that is pretty small. Here is a link to it. It powers my carputer quite well. That pic is stretched too. It actually looks like this. It doesn't show in the picture, but there are Push-Terminal connectors so you can connect bare wires as well as lighter size plugs. Dimensions (HWD): 1-7/8 x 3 x 7-1/2 Inches, Weight: .89 lbs